Question about sharing a network

In my household we have several playstation 3s which are used for online gaming as well as PCs that are used for this too.

However when other people are using the internet, the gaming systems, obviously, lag.

Is there any way to, for example, 'allocate' a bandwidth limit on to certain MAC addresses to better suit my needs? It seems illogical that people just browsing the internet should be able to seriously affect the demands of the game.

I cannot think of a solution myself so I am turning to the experts. I have had lots of help here before and am hoping someone can resolve my issue.

I suggest having a go at adjusting the QOS ( Quality of Service ) settings in your router either via MAC address , program or port to get the best connections based on needs . What router are you using ?